Answer:
Subtract your heart's resting rate from your maximum rate. For example, if you are 40 years old, subtract that number from 220; your maximum rate is 180. Next, subtract your resting rate or 80 in this example. Your heart-rate reserve is 100 beats per minute.
The first stage (dialation)
Answer:
Water
Explanation:
The main things living things need to survive are food, air, sunlight and water. You have to stay hydrated for your body to continue functioning